Samuel b



UNITED STATES PATENT OFFICE.

SAMUEL B. PIERCE, OF LA CROSSE, WISCONSIN, ASSIGNOR ()F ONE-HALF OF HISRIGHT TO CHAS. W. DILL, OF SAME PLACE.

RlNG-BURR FOR TURNING SHAFTS.

SPECIFICATION formingpart of Letters Patent No. 230,812, dated August 3,1880.

Application filed November 10 1879.

To all whom it may concern:

Be it known that I, SAMUEL B. PIERoE, a citizen of the United States,residing at La Orosse, in the county of La Crosse and State ofWisconsin, have invented a new and useful Improvement in Ring-Burrs forTurning Shafts, of which the following is a specification.

In the use of the ordinary ring-burrs for finishing the turning ofshafts the teeth are liable to he clogged by the chips crowding betweenthem.

To obviate this objection is the object of my invention.

My invention, in the first place, consists of a burr having a centralopening to receive the shaft to be turned, and a plain surface at oneside and teeth at the opposite side, in combination with asupporting-stand.

In the second place, the invention consists of a back-rest, incombination with said burr and stand, as hereinafter fully described.

In the accompanying drawings, which make a part of this specification,Figure l is a frontside elevation of the stand A and burr B with myimprovement. Fig. 2 is a rear elevation of the same. Fig. 3 is an edgeview of the same. Fig. 4. is a vertical section, on an enlarged scale,of the back-rest D and socket i, having a spring, E, and set-screw G.Figs. 5, 6, and 7 are, respectively, a rear, sectional, and front viewof the burr B.

Like letters of reference in all the figures indicate the same parts.

A is a stand,-which, in practice, is confined to a slide-rest of aturning-lathe. immediately in the rear of the ordinary chisel or cutter.

B is a burr in the opening a, at the upper part of the stand. It isconfined firmly in its place by means of the set-screw G. The burr has acentral opening, 0, which surrounds the shaft to be turned. On one sideof this opening is a plain surface, (I, and opposite thereto are thepeculiarly-formed teeth 0. Between the teeth are channels for thepassage of chips or shavings, to prevent the clogging of the teeth. Theyhave narrow parts 9 between the points of the teeth, through which thechips or shavings, as they are made by the ac tion of the teeth, slideinto the enlarged parts f. The parts 9 are narrow to admit of the teethbeing as close together as practicable for the complete operation of theburr.

Both parts, f and g, have a gradual enlargement from. the front side ofthe burr to the rear side of the same, to admit of the free outwardpassage of the chipsor shavings.

The parts f are preferably of circular form, as represented; yet otherforms will answer, if desired.

The opening a of the stand is made sufliciently large to receive burrsturning various sizes of shafts.

D is a back-rest, having a stem, h, which fits the socket i on the rearside of the stand. The socket is provided with a sprin E, which holdsthe rest up against the shaft to be turned to keep it steady. The forceof the spring is regulated by the set-screw G, there being a washer, j,between the spring and the set-screw.

The operation is as follows: As the sliderest provided with the stand A,having the burr B, is moved along from one end of the shaft to theother, as the ordinary cutting-tool takes off a shaving the burr Boperates immediately in the rear of said cutter and finishes the turningoperation, during which the shaft is held against the plain surfaced ofthe burr by the action of the spring G upon the rest D, pressing thelatter against the side of the shaft opposite to the plain surface ofthe burr, to prevent lateral shaking of the shaft, the spring yieldingto any inequalities of the shaft, to admit of the free movement of thelatter.

I claim as my invention- 1. The burr B, having a central opening, 0, toreceive the shaft to be turned, provided with aplain' surface, d, at oneside and teeth c at the opposite side, with passages g f between theteeth, enlarged from the front side of the burr to the rear sidethereof, substantially in the manner and for the purpose set forth.

2. The combination of the back-rest D, having a stem, 71 with the stand-A, having a socket, z', provided with a spring, E, and setscrew G, andwith the burr B, having a central opening, 0, with teeth 0 at one sideand a plain surface, (I, opposite thereto, substantially in the mannerand for the purpose set forth.

SAMUEL B. PIERCE.

Witnesses:

BENJAMIN F. FITCH, FREDEnIo TI-IORNELY.

